A fuel injector is known from DE 103 60 330 A1 which is used in particular for fuel injection systems of internal combustion engines. The known fuel injector includes a valve needle that cooperates with a valve seat surface to form a sealing seat, and an armature that is connected to the valve needle, and that is acted on by a return spring in a closing direction and cooperates with a solenoid. The armature is situated in a recess in an external pole of the magnetic circuit, and includes a collar that is provided around the circumference of the armature. The collar has a triangular cross section. Directionally dependent hydraulic damping of the armature is possible due to the shape of the collar, resulting in damping of the opening movement. In contrast, a virtually unhindered flow of fuel results during the closing movement, so that there is preferably little adhesion of the armature to the internal pole, and the fuel injector may be quickly closed.